What is Claim Evidence Reasoning?
Claim-Evidence-Reasoning, often shortened to CER, is a response structure in which a writer states an answer or conclusion, supports it with relevant evidence, and explains the logical or scientific reasoning that connects the evidence to the claim.
What good claim evidence reasoning looks like
A strong CER response uses a claim that answers the question, evidence that is sufficient and relevant, and reasoning that explicitly explains why the evidence supports the claim instead of assuming the connection is obvious.
- Claim: answer the question in a defensible sentence.
- Evidence: select observations, data, quotations, or facts that directly bear on the claim.
- Reasoning: explain the principle or logic connecting the evidence to the claim.
- Qualification: note limitations or competing evidence when the task requires nuance.
A practical structure to follow
Use these elements as a decision checklist, not as a rigid formula. The exact wording should still fit the reader, context, and purpose.
- Claim: answer the question in a defensible sentence.
- Evidence: select observations, data, quotations, or facts that directly bear on the claim.
- Reasoning: explain the principle or logic connecting the evidence to the claim.
- Qualification: note limitations or competing evidence when the task requires nuance.
How to write claim evidence reasoning step by step
- 1Write the claim before choosing evidence.
- 2Rank available evidence by direct relevance.
- 3State what each piece of evidence shows.
- 4Name the principle, mechanism, or interpretive logic connecting evidence to claim.
- 5Check whether the reasoning could still make sense if the claim were removed.
8 Claim Evidence Reasoning examples
Read the examples for structure and choices rather than copying surface wording. Notice what stays consistent and what changes with audience or purpose.
Claim: The unknown liquid is acidic. Evidence: It changed blue litmus paper to red and measured pH 3. Reasoning: Acids have pH values below 7 and turn blue litmus red.
Claim: The narrator is unreliable. Evidence: Two later scenes contradict details in his opening account. Reasoning: Repeated contradictions weaken confidence that his version of events is complete or accurate.
Claim: The insulation reduced heat loss. Evidence: The insulated container cooled 8°C less over 30 minutes. Reasoning: Slower temperature change indicates lower heat transfer under the same conditions.
Claim: The policy reduced late arrivals. Evidence: Late check-ins fell from 18% to 9% after implementation. Reasoning: The timing aligns with the policy change, although other schedule changes should be checked before claiming causation.
Claim: Plant B grew faster. Evidence: Its mean height increased 4.2 cm compared with 1.7 cm for Plant A. Reasoning: Greater increase over the same interval indicates a higher observed growth rate.
Claim: The speech appeals strongly to ethos. Evidence: The speaker repeatedly cites direct professional experience. Reasoning: Establishing relevant credibility is a standard way of strengthening ethos.
Claim Evidence Reasoning templates
Replace every bracketed field with situation-specific information. A template is a starting structure, not finished copy.
Claim: [direct answer]. Evidence: [specific data/detail]. Reasoning: This evidence supports the claim because [principle/mechanism].
Multiple evidence: [Claim]. First, [evidence 1]. Second, [evidence 2]. Together, these support the claim because [reasoning].
Qualified CER: [Claim], although [limitation]. [Evidence]. The evidence supports [narrow claim] because [reasoning].
Common mistakes to avoid
- Restating the evidence as reasoning.
- Using evidence that is interesting but not relevant to the claim.
- Making a broader claim than the evidence supports.
- Assuming a causal explanation from a simple association without justification.
Final revision checklist
- Does the opening make the purpose clear quickly?
- Is every important claim, detail, or example doing a distinct job?
- Could a reader misunderstand any pronoun, transition, time reference, or instruction?
- Is the tone appropriate for the relationship and situation?
- Can you remove repetition without removing necessary context?
- If the writing contains factual claims, names, dates, quotations, or citations, have you verified them independently?
Questions about Claim Evidence Reasoning
What is Claim Evidence Reasoning?
Claim-Evidence-Reasoning, often shortened to CER, is a response structure in which a writer states an answer or conclusion, supports it with relevant evidence, and explains the logical or scientific reasoning that connects the evidence to the claim.
What makes Claim Evidence Reasoning effective?
A strong CER response uses a claim that answers the question, evidence that is sufficient and relevant, and reasoning that explicitly explains why the evidence supports the claim instead of assuming the connection is obvious.
How do I write Claim Evidence Reasoning?
Start with the purpose and reader, then work through the structure in order. Draft for meaning first, check the examples for pattern, and do a final revision for clarity, accuracy, tone, and unnecessary repetition.
What should I avoid when writing Claim Evidence Reasoning?
Restating the evidence as reasoning. Using evidence that is interesting but not relevant to the claim. Making a broader claim than the evidence supports.
When should I use a first-party or primary source instead of a secondary source for Claim Evidence Reasoning?
Use the first-party or primary source when the exact fact, quotation, current requirement, project/manuscript detail, policy, metric, or source text controls the conclusion. Use a strong secondary source when the job is synthesis, explanation, field-level context, or orientation and the secondary source is appropriate to that job. If a reader could act on the claim, if sources disagree, or if wording depends on an exact passage, number, rule, or current status, escalate to the controlling source of truth and record the source, version/date, and locator before publication.
Should Claim Evidence Reasoning show one “last updated” date or track verification at the claim level?
Use a page-level revision date for editorial history, but do not let it imply that every statement was reverified on that date. Changeable facts, quotations, policies, project facts, market data, provider capabilities, and other consequential claims should carry a source record with their own last-verified date or version and a specific recheck trigger. Stable editorial synthesis and original instructional examples can use the page revision/version record instead. When a material correction, retraction, or recommendation change affects what the reader should believe or do, retain the prior record and disclose what changed and why.
How do I know whether a claim or source on a Claim Evidence Reasoning guide is stale, corrected, or still active?
Do not infer status from the page-wide update date. Check the controlling source or project record, the exact version/date last verified, and the trigger that could make the item changeable. Keep it active when the source still controls the exact claim; mark review due when a trigger has fired but the conclusion is not yet disproved; mark stale when the old version no longer controls; and use corrected, retracted, withdrawn, or superseded when the editorial history requires it. The correction level should match reader impact: cosmetic edits are not the same as a material factual correction or a critical source failure.
If a source behind Claim Evidence Reasoning changes, how do I know which other claims or guides need review?
Use the dependency map rather than reviewing the entire site blindly. Identify the exact claim or example that depends on the source, classify the dependency as direct, shared, advisory, or independent, and record why the source changed. Direct dependents should be reviewed immediately when a controlling source is corrected, retracted, superseded, or no longer supports the claim. Shared dependents can be queued by source/claim ID and scope. Replace the source only when the replacement performs the same evidentiary job—or change the claim. Keep the old source/status in the ledger, then propagate the review to templates, examples, and related guides only where that dependency actually exists.